It is well known that leaks in a pipeline are harzardous to the personnel working around the pipeline and wasteful of the material being carried therethrough. Such leaks may occur through the pipe sections, such as straight conduit, elbows and valves, and through the flange joints used to connect the sections to one another.
A recent development in stopping such leaks has been the use of leak repair clamps. Such clamps normally include a body forming a cavity between the pipeline and body for receiving a liquid sealant and a passageway communicating with the cavity for directing the sealant thereto. Thus, the sealant is injected through the sealant passageway into the cavity for originally sealing the leak in the pipeline. A plug is then positioned in the passageway to prevent the sealant from draining or being blown from the clamp and to prevent foreign matter from entering the clamp and polluting the sealant.
Frequently, a leak develops after a leak repair clamp has been positioned about the pipeline. Some reasons such leaks develop in the previously sealed area is that the sealant may become brittle or cracked around the sealed area. Another reason is that the material carried through the pipeline may act as a solvent on the sealant, thereby eroding the seal. If the leak is reopened then it becomes necessary to once again attempt to seal the leak.
Heretofore such second and subsequent attempts required that the clamp be removed, the old sealant scraped away and another clamp and new sealant placed thereon or that a drill and tap procedure be used to drill into the cavity and inject more sealant therein.
One other method is to remove the plug used to stopper the passageway after injection of the original sealant but plug removal is sometimes quite difficult and hazardous because the plug has become attached to the clamp by rust or corrosion; consequently when the plug is removed the material being carried in the pipeline is then free to flow out the sealant passageway, possibly creating health and property hazards. Thus, a problem exists in re-opening the sealant passageway to permit injection of additional sealant into the cavity. After the plug has been removed and the sealant added, the sealant passageway must be restoppered. Thus, care must be taken in removing the plug which requires a substantial amount of time and is quite expensive.
In accordance with the invention a method of and apparatus for sealing a leak in a pipeline which includes a leak repair clamp for sealing a leak in a pipeline. The clamp includes a body forming a cavity for receiving sealant to seal the clamp to the pipeline and a passageway provided in the body that communicates with the cavity for directing sealant thereto. The leak repair clamp is mounted to the pipeline and sealant is injected through the sealant passageway into the cavity to seal the clamp to the pipeline. A plug is mounted with the clamp to stopper the sealant passageway in the clamp, the plug includes a head portion and a mounting portion with threads disposed thereon for threadedly engaging threads within the sealant passageway to stopper the sealant passageway with the plug. A blind passageway extends through the head portion of the plug and into the mounted portion to terminate at a plugging wall. The blind passageway is of sufficient size to permit apparatus access to the plugging wall for drilling therethrough so that more sealant may be added to the cavity without removing the plug from the clamp.